1. Technical Field
The present invention relates to an illuminator and a projector.
2. Related Art
As an illuminator for a projector, there is a known illuminator in which fluorescence produced by exciting a phosphor with excitation light emitted from a solid-state light source is used as illumination light (JP-A-2012-137744, for example). In the illuminator, the light emitted from the solid-state light source passes through a half-wave plate, which converts the light into light containing S-polarized light and P-polarized light, and the converted light is incident on a dichroic mirror (polarization separation element). Out of the light incident on the dichroic mirror, the light formed of the P-polarized light component passes through the dichroic mirror, and the light formed of the S-polarized light is reflected off the dichroic mirror. In the illuminator, the polarization ratio of the light incident on the dichroic mirror is controlled by adjustment of the angle of rotation of the half-wave plate.
In the illuminator described above, however, a mechanism that rotates the half-wave plate is used to change the polarization ratio of the light incident on the polarization separation element, undesirably resulting in an increase in cost.